document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=751125>Question 751125</A>: <I><SPAN STYLE=\"word-break: break-all;\"> the max population that earth can sustain is 40 billion. if the current population is 4.2 billion, in how many years will the max population be reached? Assume that each year the population is 2% more than the previous year. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #456998 by </B><A HREF=/tutors/aboutme.mpl?userid=nerdybill><B>nerdybill(7384)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=nerdybill><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=nerdybill><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=456998\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">     the max population that earth can sustain is 40 billion. if the current population is 4.2 billion, in how many years will the max population be reached? Assume that each year the population is 2% more than the previous year.<BR>\n" );
document.write( ".<BR>\n" );
document.write( "Exponential growth equation:<BR>\n" );
document.write( "A = Pe^(rt)<BR>\n" );
document.write( "the problem give us:<BR>\n" );
document.write( "P is 4.2<BR>\n" );
document.write( "A is 40<BR>\n" );
document.write( "r is .02<BR>\n" );
document.write( ".<BR>\n" );
document.write( "40 = 4.2e^(.02t)<BR>\n" );
document.write( "40/4.2 = e^(.02t)<BR>\n" );
document.write( "ln(40/4.2) = .02t<BR>\n" );
document.write( "ln(40/4.2)/.02 = t<BR>\n" );
document.write( "112.69 = t<BR>\n" );
document.write( "or<BR>\n" );
document.write( "113 years = t\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );